1. Field of the Invention
The invention relates to vacuums in general and to cyclonic vacuums in particular.
2. Prior Art
Cyclonic vacuums are well know in the art. For example, U.S. Pat. No. 4,373,228 to Dyson discloses a cyclonic vacuum. Such vacuums offer advantages over traditional vacuums in that they either require no conventional filter or, more commonly, the cyclonic action keeps dust and dirt away from the conventional filter, thereby preventing it from clogging. This tends to both prolong the life of the conventional filter and prevent a decline in the overall strength of the vacuum as the filter clogs. However, many cyclonic designs impede vacuum strength. In most cyclonic designs, cyclonic motion is imparted by configuring the air to enter the cyclonic chamber at a significant angle relative to the path the air exits the cyclonic chamber. This angular or tangential entry creates a vortex within the cyclonic chamber. However, the hard turn in the air path necessarily slows the flow of air as it enters the cyclonic chamber. Slowing the flow of air lessens the strength of the vacuum. As a result and with all other things being equal, the suction of most cyclonic vacuums will be weaker than the suction provided by a conventional vacuum with a similar motor and fan. The length of the passage through which air must pass increases resistance, slowing the air and weakening the strength of the vacuum. Thus, the addition of attachments to any vacuum will reduce its strength. This weakening is enhanced when the attachment is added to a cyclonic vacuum wherein the cyclonic flow is induced by tangential entry to the cyclonic chamber.
In other prior art cyclonic designs, cyclonic motion is imparted via a curved nozzle. These vacuums have their own associated problems. In such vacuums, the air inflow passage leads into a nozzle which extends into the cyclonic chamber. As air enters the nozzle and into the cyclonic chamber, the curvature of the nozzle causes the air to hit the side of the wall at an angle, creating cyclonic motion. However, because the body of the nozzle itself extends into the cyclonic chamber, it acts as a physical obstruction to the cyclonic motion of the air. This in turn substantially inhibits and/or destroys the cyclonic motion and slows the flow of the air. As a result, the suction strength of the vacuum is weakened.
In view of the foregoing, a cyclonic vacuum meeting the following objectives is desired.